Whink® Rust Oxy Stain Remover. Outdoor rust stain remover. Patios. Driveways. Sidewalks. Signs. Siding. Brick. Stucco... and more. Net wt 2.25 lbs (36 oz) 1020.58 g. Safe in septic tanks. Contains no phosphates. Comments, Questions: Call weekdays 9-4 CST. Toll free 1-800-247-5102. www.whink.com. ©2017 Whink Products Company.